Manufacture of carbid.



trim or MINNESOTA.

Specification of Letters Patent.

HERMAN L. HAa rEN's rEIN, OF OONSTANTINE,

MENTS, TO CONTINENTAL INVESTMENT COM MICHIGAN, ASSIGNOR, BY MESNE ASSIGN- MANUFACTURE OF CA-RBID.

Patented May 26, 1908.

original epplication flledlFebruary 13, 1907, Serial No. 357,140. 'Divided. and this application filed. .Iulyv 17, 1907.

r0 Gimme ma co'ncc'rn:

Be 1t. known that I, HERMAN L. HARTEN- strum, =a*bi tizen of theUnited States, residmg at (Jonstantme, 1n the county of StIJoeeph and State of Michigan, have invented certainnew and useful Improvements in the Manufacture of Garbid, of which the followi is a full,'.clear, and exact 'specificationi his invention relates more particularly to the manufacture of calcium carbid from limestone orflime and a carbonaceous ma- ];terial such as coal, etc., and it has for its primary objecta method in which all of the advantages of the use of coal may be secured without any of the disadvantages of such than lump coke and contains muc element, such as excessive smoke generated intthe furnace during, the reduction operaion "and the higher or excessive voltage re;

" by reason of the presence of the parof. hard coal in the charge being treated uced,

other object of the invention-is. to provide' an improved method for the manufactareof carbid in which the small .particles of lime or limestone will be bound into intimate association with the small particles of carbonaceous material during the reduction of the same in the electric furnace.

. In'carrying out the invention, I employ lime and, carbonaceous material in the usual or any suitable proportions as heretofore racticedin this art and the lime obtained in the usual orany suitable way but preferablybylcalcining limestone which has been gileviously pulverized or comminuted. The

eor calcined limestone is taken from the re-heater or calcining furnace while in its highly heated condition and is mixed with the'proper proportion of carbonaceous matter which, according to this invention, conslsts of a mixture of hard coal (anthracite coal) and coke, or charcoal. I preferably employ anthracite coal screenings, which are in a more or less fine or comminuted condition and to'eighty or ninety per cent. of which I add from ten to twenty er cent. of the coke or charcoal, which-is a so previously ground or powdered. By using anthracite coal' and coke it is practicable to utilize the cheaper grades of coke as, for: example, breeze or refuse which is higher in ash and im urities more than the anthracite coal. These two ingre- Serial No.

dients are intimately commingled and mixed with the fine or pulverized lime or limestone while the latter .is in itshighly heated con. dition and the mass is then subjected to the action of the electric current in an electric furnace until reduced to a bath according to the established practice of this art. The anthracite coal is rich in carbonaceous material but its use is attended by objectionable results, such as excessive smoke which precludes a fair view of the electrodes when the furnace is opened for examination by the attendant from time to time during the operation and, moreover, it furnishes a high resistance to the current and as a consequence requires a higher voltage. These objections however, are sufficiently overcome by the addition of the percentage of coke or charcoal which adds greatly to the conductivity of the charge between. the electrodes.

The result may be still further im roved and facilitated by the addition to t e carbonaceous constituent of a small percentage (say from three to twenty per cent.) of bituminous coal, rich in tarry compounds, say about five per cent. This, also, 1s employed in a state of fine sub-division and it is mixed with the lime or calcined limestone while the latter is in its highly heated condition after coming from the pre-heater or calcining furnace and by thus intermingling the bituminous coal with the lime pr calcined limestone while the latter is hot it is converted into coke and its constituent is more or less liquefied or softened and deposits itself upon the particles of calcined limestone well as upon the particles of coke and ant macite coal and acts as a binder to hold these constituents of the carbonaceous material into intimate association with the lime, thereby giving every particle of lime its appropriate percentage of carbonaceous material and resulting in a final product which 'pre sents a degree of uniform reduction greater than that heretofore secured. 1

The soft coal may also be mixed with the anthracite or coke before being placed in the mixer with the highly heated imestone.

The temperature is sufficiently high to convert the tar and carbon of the coal'into coke, and previous to or during the process of mixing it servesto act as a binder for holding together, the coke, anthracite and highly PANY, OF DULUTH, MINNESOTA, A CORPO- heated limestone of the charged mixture, while the soft coal is likewise converted into a-coke and becomes a portion of the char e mixture when it leaves the mixer and is placed in the electric furnaces.

It is understood that the articles of, hot limestone and coke and ant racite coalbecome more or less mechanically united while the tar matter of the soft coalisbeing expelled t erefrom and converted into cokg.

The volatile matter-or gases that are expelled during the mixing process furnish heat elements, and at the same time'materially aid the mechanical mixing process, by reason of the boiling or agitation caused by the volafiile matter of the soft coal in the presence of eat.

The gases produced by the addition of soft coal are also ample to prevent the admission of air into the mixture and thereby prevent any possible oxidation of other carbonaceous material (anthracite or coke) which is low in subject matter of the claims of my applioa-t tion Serial No. 357,140,

filed February 13th,

Having thus described 111 invention, what I claim as new therein and esire tosecure by Letters Patent isp A composition of matter for use in the manufacture of carbid, consist of lime, bituminous coal, coke or charcb afi and anthracite coal. f

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, on this eighth day of July A. D. 1907. p

HERMAN L. HARTENSTEIN. Witnesses:

H. E. SMITH, W M. H. BROWNRIGG. 

